All,  Finally pulled this off of the back burner of 'things to do'.

Problem was a case of rear steer...one way under accel, the other under
decel.  I pulled the arm out and of the six pairs of bushings there was
only one complete pair left (upper, right).  All of the others had
broken up into little chunks and powder.  This car is auto-x'd so it
gets some pretty severe side loading.

A friend's brother had a similar experiance while launching his car at
FFW/Houston.  He heard a loud metallic sound when launching...no rear
steer, but same cause.  Both car's control arms are about five-six
years old.  Both cars had the bushings greased regularly.

MAC is replacing the bushings for free as they admit they had problems
with an outside supplier.  I'm sending a zip-loc bag full of bushing
remains.

If you have 'em, but no symptoms try this...grab the top of the rear
tire and push/pull HARD and listen for any metallic sound.  Visually
check that the outside lip of the bushing to see if it conforms to
control arm.

bradtx